Estudios científicos

Dietary intake of pterostilbene, a constituent of blueberries, inhibits the {beta}-catenin/p65 downstream signaling pathway and colon carcinogenesis in rats.


Stilbenes are phytochemicals present in grapes, berries, peanuts and red wine. A widely studied stilbene, resveratrol (trans-3,5,4'-trihydroxystilbene), has been shown to exert anti-oxidant, anti-inflammatory, chemopreventive, and anti-aging effects in a number of biological systems. We reported earlier that pterostilbene (trans-3,5-dimethoxy-4'-hydroxystilbene), a structurally related stilbene found in blueberries, was effective in reducing the incidence and multiplicity of aberrant crypt foci formation in the colon of rats injected with azoxymethane (AOM). Our present study was to identify the chemopreventive potential of pterostilbene with colonic tumor formation as an end point, and further to evaluate the mechanistic action of pterostilbene during colon carcinogenesis. F344 rats were given two AOM injections subcutaneously when they were 7 and 8 weeks old, and continuously fed the control or 40 ppm pterostilbene diet for 45 weeks. Overall analyses indicated that pterostilbene reduced colon tumor multiplicity of non-invasive adenocarcinomas, lowered proliferating cell nuclear antigen, and down-regulated the expression of beta-catenin and cyclin D1. Pterostilbene decreased mucosal levels of the pro-inflammatory cytokines, TNF-alpha, IL-1beta and IL-4. Colon tumors from pterostilbene fed animals showed reduced expression of inflammatory markers as well as nuclear staining for phospho-p65, a key molecule in the NF-kappaB pathway. In HT-29 cells, pterostilbene reduced the protein levels of beta-catenin, cyclin D1 and c-MYC, altered the cellular localization of beta-catenin, and inhibited the phosphorylation of p65. Our data with pterostilbene in suppressing colon tumorigenesis, cell proliferation as well as key inflammatory markers in vivo and in vitro suggest the potential use of pterostilbene for colon cancer prevention.

Comentarios divulgativos:

Los estilbenos son compuestos presentes en uvas, bayas y vino tinto. Hay un amplio número de estudios basados en las propiedades antinflamatorias, antioxidantes y quimiopreventivas del stilbeno y el resveratrol en diferentes organismos. El estilbeno encontrado en arándanos es efectivo reduciendo la incidencia de la formación de estructuras aberrantes en el colon de ratas inyectadas con azoxymetano (AOM). Nuestros datos sugieren que el pterostilbeno suprime la tumorogénesis en colon, la proliferación celular y algunos marcadores inflamatorios in vivo e in vitro. Mostrando un posible uso de este compuesto en la prevención cancerígena.